Control and protection device for fulling machines



Sept, 26, 1961 A. BERTOLDI CONTROL ANO PROTECTION DEVICE FOR FULLING MACHINES Filed May l5, 1959 Unite ares The present invention relates to a device for effecting an upward movement ofthe upper roller of a fulling machine in case of knotting or entanglement of the fabric piece'during the fulling operation.

arent `.Two basic types of fulling machines are known. Aci cording to one of such types the fulling machine is provided with a hammer, which by its movement within a closed chamber and by cooperating with inner oscillating walls of the said chamber eects the fulling orfeltin; of the piece of fabric. Such a type of fulling machine is to be regarded as obsolete because of its low production and the damage that it causes to the fabrics. Machines of the other type, `which include the one proposed by the invention, present a closed chamber, a pair of rollers of which at least one is driven by a motor, and two essentially Vparallel walls ,forming a channel through which moves the fabric discharged by the rollers. A 'third wall delimiting Athe channel is loaded by springs or counter-weights pressing the said wall downwards and permitting it thereby to exert its maximum pressure upon the. fabric. q

Pressure on the fabric is also exerted by said pair of rollers one of which is loaded by a system of` springs. This latter apparatus has the disadvantages that it does not allow of changing the work in a practical manner and does not prevent the possibility of the rupture of the fabric inV the case of knots. Finally it does not permit of adequately distributing the working pressure between the pressure rollers as required by the particular type of fabric under treatment.

The invention aims at the above drawbacks.

According to the present invention, a device is provided for the control and protection of fulling machines having a pair of rotating pressure rollers which transfer the fabric piece into a channel defined by two walls, of which at least one is movable, and in which one of the pressure rollers is pivotally mounted to be hydraulically or pneumatically lifted undei the action of a feeler which detects the presence of knots or entanglements and acts upon a circuit of fluid under pressure causing instantaneous lifting of said one of the said pressure lrollers before the knot or entanglement can reach the said pair of pressure rollers, thus avoiding damage to the fabric piece.

According to another inventive feature, the circuit of huid under pressure is controlled by the feeler device through an electric circuit which causes on one hand the stopping of a driving motor of the fulling machine and, on the other hand the operation of electromagnetic valves controlling the movement of the fluid under pressure.

According to another inventive feature, there are interposed in the hydraulic or pneumatic circuit manual regulators for the tiuid pressure which, being associated with Suitable reading instruments, for instance of the pressure gauge type, allow of adjusting the pressure exerted by the movable pressure roller upon the piece of fabric.

Another inventive feature resides in the possibility of displacing, by means of the iiuid under pressure, one of the walls defining the channel into which the pressure rollers introduce the piece of fabric.

The invention will be further described with reference to the accompanying drawing, which represents a schematic longitudinal cross-section of a fulling machine with a compressed air circuit represented by a block diagram.

realizing a solution exempt from Vcuit as the motor ice The machine shown comprises a work chamber generally indicated by 1, a front inlet door 2, and a rear door 3, as well as a pair of pressure rollers 4 and 5, at least one of which is driven by an electric motor (not shown) and between which passes the fabric piece (not represented) which is to undergo the fulling operation. The fulling machine further comprises two walls 6 and 7 defining a feed channel 8.

The wall indicated by 6 can be moved nearer to or further away from the adjacent wall 7 by means of -a mechanical `connection 9 which is actuated by a pneumatic piston ltia. The pneumatic cylinder 1t) for wall 6 is 'controlled by the same circuit as that of cylinder 16.

As shown in the drawing, the wall 6 is connected with the movable piston 10a of a pneumatic cylinder 10 by means of a linkage arrangement 1Gb, 10c, 10e 10i which is of a conventional type and will not therefore be described in detail.

By regulating the air pressure in the cylinder 10 it is possible to influence the pressure exerted by the movable wall `t5 upon the piece of fabric running through the channel 8. i

Rollers 11 and 12 are further provided in the lower and upper part of the apparatus serving to transfer the fabric, which movesin the direction indicated by the arrows A, from the upper portion of the chamber 1 to the lower portion thereof. j

According to the invention, the upper roller 4 is pivotally mounted as to be able to swing around an axis 13 by the action of a System of adjustable bars `1li terminating `at the `rod of a piston 15 slidable in a fixed pneumatic cylinder 16.

The cylinder 16 is fed from an air compressor K through a main cock 17, an actuating lever thereof being placed upon a control panel (not represented) and located in the front of the machine.

Compressed air issuing from the cock will be shown more particularly below, an electromagnetic valve 18 or an valve 19.v

In the first case, the compressed air arrives at two pressure reducers 20 and 21 communicating with their respective pressure gauges 20a and 21a. The said pressure reducers 20 and 21 can be manually controlled at all times from the control panel through knobs 22 and `23 which permit of varying the pressure in lines 24 and 25 leading to two `opposite cylinder chambers 16a, lfb of the cylinder 16'. Numeral 26 denotes a three-way valve which canbe controlled manually or by means of suitable electric device and permits of releasing to atmosphere the compressed air contained in the cylinder 16. The said valve can be also controlled from the control panel of the fulling machine. The other branch or pipe 2S of the pneumatic circuit is controlled by the electromagnetic valve 19, whilst the channel 24 can be put in communication with the atmosphere through a third electromagnetic valve indicated by the reference numeral 29.

Immediately above the roller 12 there is provided a feeler device 30 which is adjustable and is pivoted at 31, such feeler device being adapted to actuate with its end 32 a switch 33, thus causing the stopping of the motor and cutting off of the current to the electromagnetic valves 18, 19 and 29 which are fed by the same electric cirdriving the machine. The lever 33 is immediately lifted by the presence of an entanglement such as a knot or Something else on the piece of fabric, effecting the stopping of the motor and the immediate lifting of the pressure roller 4 by means of the air under pressure acting upon the lower face of the piston 15.

The operation of the machine is as follows:

Before starting work, i.e. when the fulling machine is 17 can pass, as through either electromagnetic stationary, the valves 19, ,Z9 whereas the valve 18 is in a closed position. In this case the compressed air passes through the pipe 28 into the pipe `25 and enters thecylinder -1j6 Lunderneath the piston which is therefore lifted, because t-hef;upper chamber of the said cylinder vcommunicates withnthe atmosphere through-the electromagnetic valve 29.

At the start of the fulling operation the three-electromagnetic valves 18, 19,.-29 are fed'withcurrent derived from a remote control switch of the motor (not illustrated). The valve 18 consequently opens andthe valves 19 and 29 close. VIn these conditions, the lthree way valve 26 being supposed to be closed and the cock 17 open, the .cylinder 16 is fed with iluid Vat the twosides of its piston 15,and by suitably adjusting by means yof the :knobs 22 and 23 the pressure reduction of the air coming from the compressor K, it will be possible to exert upon thel fabric piece a gradual pressure at will, whichl pressure will correspond with the indications kof pressure gauges 20a ,and 21a. Y

Should the lever 30 be lifted on account of the presence of a knot or entanglement of the fabric, lthe switch 33 will be operated and therefore the electric will ybe opened; the valves 19 and 29 will change to the open position and the valve 18 will be closed. By virtue of such movementsthe piston y15 is quickly lifted and `the pressure roller 4 is raised with it.

In order to restore the roller 4 Vto its workingposition, after having loosened the knot, the cock-17` isv rst shut and then the air of the cylinder 16 is dischargedthrough the three way valve 26. `After the 3-way -valve Vis opened to allow upper roller 4 to recede .against lower roller '5, the three-way valve will be immediately closed again. VWhen the fulling machine is'started Iagain `and the cock 17 is opened, the valves return to their working position and the pistons -to the previously established pressures by means of the pressure reducers 20 and 21.

A basic advantage of the proposedsolution consists in that the stopping of the motor and the lifting of the roller 4 take place before the obstruction arrives between the Vrollers 4, 5, thus preventing tears and breakages. Another advantage is to Ibe appreciated Vin thepossibility of providing automatic protection on old installations by means of simplextures. Further, manually lifting the roller 4 is done away with, which renders operation quicker. The cushioning effect of the air entrapped within the cylinder 16 leads to -a better fullingaction. It is possible to adjust, within ample limits and ,with greater sensitivity, the pressureexerted by-the roller-4 and wall 6 upon the fabric yandto work accordingto scientific criteria, thus Vensuring a product having uniform characteristics. Lastly, the possibility of controlling the maare l in an vopen position :comprising in combination wChine. fromtaentral panel renders 4the workeasy tothe the presence lof knots Vand entanglements thereon; a :compressed air circuitfor controlling the pressure betweensaid pressure rollersthrough said swingable member and for displacing said one of said pressure `rollers when saidfeeler device detects, the presence .-.of` knots, entanglementsvand the like; thesaid compressed air circuit a source of compressed air; two pipes connected to said source; twopressure reducers branched respectively to said two pipes, each pressure reducer being provided with manual controlpmeans and associated each to a pressure indicating device; `a pneumatic. cylinder fed by said twotpipes; a piston mounted in y `said pneumatic cylinder .and subject .to differential pressure generated by air supplied. through said two pipes, one of said pipes being connected to the lower portion of said cylinder below said piston and the other of said pipes being connected to the upper portion of said cylinder abovesaid piston; mechanical means connecting said piston to said swingable member sozas to cause varation--of pressure between said pressure rollers.

2. A device as claimed in claim 1, in whichssaid compressed-'air circuit-comprisesfurther in combination a thirdpipe'feeding into said one ofthe said two pipes from Asaid source; a irst electromagnetic valve insertedbet-Weensaid two pipes and said source of compressed air andset in `a closedpositon-only when said feeler device is actuated, asecond electromagneticvalve vinserted-in said thirdpipe andsetjin an open position when said feeler-device is actuated.

3. A device as claimed in claimlrin which said feeler device comprises a swinging lever, oneend of saidlever being associated with a feeling roller ,andthetpther end controlling ,saidl electromagnetic valves.

References Cited in the filey ofk this patent 'UNITED STATES PATENTS y 634,943 Hopkins Oct. v1'7, v1899 2,146,450 Simonds et al Feb. 7, 1939 ,FOREIGN PA']`EN'I`S Y t 28,583 -Great Britain of 19,09 

